6MM IDEAS

well I stumbled into a couple one day auctions and bought 10 matt finish 243 win barrels in standard profile for a remington 700 action. and I have 3 on hand now.

I just bought a 6mm-284 reamer so one of those is getting built for sure on a 308 saiga. I have been eyeballing the 6mmAR turbo 40 , the 6mm ppc, and a wildcat 6x39 of my own design.

there not heavy barrels so a super long range varmit gun is out but there is some options here.

The 6.5x284 will get bullets going over 4000 FPS if loded to 51,000 CUP. a light load version at 42,000 cup MIGHT be doablle on a yugo trunion and it will go 3738. I got the reamer an barrels so why not add it to the switch barrel build.

1Biggun, you'd might be disappointed with the performance of the 6x45/6mm-223. I have one and although both of the barrels I've had will shoot under 1/2" at 100yds with proper handloads, its slow. I like the idea of my ar shooting something bigger/heavier than a .224" bullet, but it does it at a velocity loss compared to other 6mms. Weight for weight its right there with the 223 for velocity, but compared to a 243 win its a dog. It is powerful enough though for deer under 100yds with heavy bullets and when ever my son is ready to go I'll most likely have him take it on his first deer hunt. The recoil is the same as the 223 and he has been shooting that for three years now. I had hoped to take him deer hunting in MO this past fall, but he wasn't ready yet. The shoulders are easily set back when crimping and its easy to mix it up with 223 ammo. I use nickel plated brass for the 6mm ammo to help prevent that.

The nickle plated is a good idea for keeping things sorted. Im going to have like 5 308 based rounds and I have been looking into coloring brass some how to avoid mix ups. there is not a lot of differance between a 243, 260, 7-mm-08 308 they all use the same head space guages. on top of it im forming 300 savage brass from 308 as well.

The 6mmAR turbo is a good one that Im looking at it uses grendal brass with the neck moved a little. I still think a simple necked down 6mmx39 would offer decent performance and feed really good for both combat as well as sporting use. It wont be no grendel or 6mm AR but it will still be lots faster than a 6mm 223 or a 7.62x39. I bet it would go 3000 FPS with 55 grain bullets may be better. the case is bigger than a 223.

on a Ak its pretty hard to beat a 243 conversion loaded under max. Its simple and brass is avaliable.

there is a 6mm bench rest that would be a good canidate for a AK length mag as well as a 6mm-1.5" based on cut down 308 cases. well I have 13 barrels to play with so some thing will work out. A 45,000 PSI 243 likely will be first maybe in a pistol.

I have the 6-284 reamer coming and it will give at least a 100 FPS more with the same pressures however brass aint cheap. Im definatly going to build one and try it loaded to the max on the Sagia 308 Id like a heavy fast twist barrel for that.

the 6mm benchrest an 6mmx1.5" barnes type is basicaly a 6x39 with 308 case.

In a AK length mag the 6mmAR turbo is about best performing that will double stack and would use a common 223 mag. It uses reformed Grendal brass. uses a standard bold face.

The 6mm PPC is good as well and dies and reamers are common how ever brass is expensive. unless formed from 7.62x39 brass and then you likely need forming dies. It uses a standard bolt as well

The 6mmx39 is not as common but there are reamer prints out there and dies are avaliable but are a custom order. 220 russian can be opend up or fire formed easly but 220 russian is not cheap. 7.62x39 can be shrunk down not sure how easly. this round would be a barrel swap only and the factory x39 mag should work.

30 BR needs a opend bolt face, not sure what mag would work, brass is easy but not cheap or you can make from cut down 308, 30-06, 243 ect. this would be more work but can be done.

there is also the 223 WSSM round that can be opend up and shortend slightly but on a standard AK trunion an bolt You really shouldnt load it to max pressures and it wont double stack.

there is also a 6mm- 6.8 SPC wild cat that really dont offer any thing special needs a special bolt and none of the AK mags work well with but its out there.

there are also a slew of pistol bassed wildcats that could be used to make a really cool blow back. a 6mmx25 comes to mind. I wonder if the surpluss 7.62x25 could be necked down with out anealing? just pull the bullet dump the powder neck down and reload. it would be dirt cheap. That brass is pretty crappy. a 9mm case necked down would be cool it would use a 5.45 bolt andbrass is cheap just neck it down.

In the 308 length mag well it would be tought to beat a plain ol 243 but I have 6mmx284 coming so Ill do at least one. we get into whata safe pressure but if I keep it under 45,000 PSI some really good performance can be had. A 243 calibur conversion for me is not much harder than a any other build.

Isn't the 243 just a fancy way of saying 6x57? If I'm thinking straight I believe that's really nothing more that necked down 7x57 or 8x57 which in my opinion would be a pretty standard conversion now here's something fun to think about, how about 6x68mm necking down 6.5 or 8x68mm s cartridges hehe basicly a very stretched case or even simply a 6mm-06. You could load them either light or maybe also use slower powder to keep pressure down but maintain speed. Just a thought

No the 243 is a necked down 308 win or 7.62x51. 234, 260,7mm-08,308, 358win all share the same 51mm/2" case and use the same head space guages.

there is not much gain in going with a 6mm-06 over a 6mm-284 as there about the same case capacity and over bore to already there about the end of the range were there is any barrel life to speak of. the 6mm-284 will give about 150 FPS more at about the same pressures in a long barrel The 243 was a wildcat at one point and is a damm good round as is. going to a longer case gets much more labor and cost intensive as its pretty tough to use standard bolt and carrier. a 6x57 can be done as could a 257 roberts and a 6mm remington they are basicaly necked down 7x57 cases but they dont fit a 308 mag very well.

I can do a 243, 260 7mm-08, 308 pretty cheap on a standard length flat and use a stock carrer and slightly moded bolt and cheap 308 mags. and all the stock barrel parts can be saved as well as the furniture covers ect. any longer and things get much harder.

Im going to make some slightly longer flats and recivers (orderd the metal today) to allow me to move the trunion forward about a 1/4" the hammer should still hit the pin ok with some mods and this will allow me to retain a normal trigger guard clearance and cross member position. Ill move the RSB back so the dust cover still fits there will be a slight gap were the RSB extends pas the trunion but it can be filled. the gas tube will fit as I will be making the barrel so ill just move it back. there will be a little work to get the fore grip into the longer reciver but it wont be much.

I honestly can do a 308 length conversion on a barreless kit cheaper than I can do a 7.62x39. on the 243 the barrel will be about $25 the mag will be $2 and the flat will cost me a round $4. rails are about 75 cents each cross member is about a quarter.. Of course there is a huge labor differance but thats the fun part. brass is about the same as a 7.62x39 and If I buy once shot 7.62x51 and reform it its even cheaper.

Hand loading is the key to most of these conversions. 300 savage and 35 remington likely can be shot as is. Im not saying 308 cant but the jury is still out on runing 61,000 PSI loads IMOO. 45,000 Psi will still give a lot of performance and peace of mind.

The 308 Sagia is the one that will get loaded up in 6mm-284 for long range shooting.